1. Field of the Invention
The present invention relates to a printed wiring board and a method for manufacturing a printed wiring board.
2. Discussion of the Background
In recent years, the structures of the wiring and pads of a semiconductor element have become finer, and the pitch of bumps in a printed wiring board on which the semiconductor element is mounted has also become finer. As a result, opening portions formed in solder-resist layers are becoming smaller. In particular, the diameter of opening portions is made extremely small. As a printed wiring board, a printed wiring board is suggested where pads for mounting an electronic component are formed on an interlayer resin insulation layer while a solder-resist layer is formed as an outermost layer. Opening portions are formed in the solder-resist layer to expose the pads, and solder bumps are formed in the opening portions (for example, see WO 2006/082784). The contents of this publication are incorporated herein by reference in their entirety.